A simplified presentation of Einstein's unified field equations, by Tullio Levi-Civita. Authorized translation by John Dougall. Levi-Civita, Tullio, 1873-1941. Dougall, John, 1867-1960, tr. Einstein, Albert, 1879-1955. Zur einheitlichen Feldtheorie. Gravitation. Electromagnetism. QC6.E57 L4 19 512.1 LES London, Blackie, 1929. 1929. 1929 Text 22 p. eng